Methods and apparatus for detecting ack/nack bits with dual list-rm decoder and symbol regeneration for lte pucch format 3

ABSTRACT

Methods and apparatus for detecting ACK/NACK bits with dual list-RM decoder and symbol regeneration for PUCCH format 3. In an exemplary embodiment, a method is provided for detected ACK/NACK bits received in a long-term evolution (LTE) physical uplink control channel (PUCCH) Format 3 uplink transmission. The method includes generating Top-M ACK candidates from a descrambled bit stream, regenerating Top-M candidate symbols from the Top-M ACK candidates, calculating channel estimates for the Top-M candidate symbols, combining to the channel estimates generate a combined metric; and searching the combined metric to determine detected ACK bits.

PRIORITY

This application is a continuation of a U.S. patent application havingan application Ser. No. 16/264,328, filed on Jan. 31, 2019, and entitled“Methods and Apparatus for Detecting ACK/NACK Bits with Dual List-RMDecoder and Symbol Regeneration for LTE PUCCH Format 3,” which furtherclaims the benefit of priority from U.S. Provisional Patent ApplicationNo. 62/663,570, filed on Apr. 27, 2018, and entitled “Method andApparatus for Detecting ACK/NACK Bits for Carrier Aggression with DualList-RM Decoder and LUT-based Symbol Regeneration for PUCCH Format 3,”all of which are hereby incorporated herein by reference in theirentirety.

FIELD

The exemplary embodiment(s) of the present invention relates totelecommunications network. More specifically, the exemplaryembodiment(s) of the present invention relates to receiving andprocessing data stream via a wireless communication network.

BACKGROUND

With a rapidly growing trend of mobile and remote data access over ahigh-speed communication network such as 3G or 4G cellular services,accurately delivering and deciphering data streams become increasinglychallenging and difficult. The high-speed communication network which iscapable of delivering information includes, but not limited to, wirelessnetwork, cellular network, wireless personal area network (“WPAN”),wireless local area network (“WLAN”), wireless metropolitan area network(“MAN”), or the like. While WPAN can be Bluetooth or ZigBee, WLAN may bea Wi-Fi network in accordance with IEEE 802.11 WLAN standards.

Typically, wireless network performance depends in part on the qualityof the transmission channel. For example, if the channel conditions aregood, the network may perform with higher speed and capacity than whenthe channel conditions are poor. To obtain the best network performance,wireless networks may rely on user devices (e.g., user equipment “UE”)to report control information back to the network. The controlinformation includes parameters indicating the channel conditions and/ortransmission parameters.

In the Third Generation Partnership Project (3GPP) Long-Term Evolution(LTE) standard, a Physical Uplink Control Channel (PUCCH) carriesimportant control information, such as HARQ-ACK bits or SR bits forcarrier aggregation. The performance of ACK messages play an importantrole in the overall downlink performance as the residual error rate ofHARQ is in the same order of the feedback error rate of ACK bits. Forexample, after a user device receives a transmission from a networkserver, it generates acknowledgement (ACK) bits that indicates whetheror not the transmission was properly received. The ACK bits aretransmitted back to the network server through the PUCCH. The server candetermine from the received ACK bits whether the transmission wasproperly received, and initiate a retransmission if necessary.

Therefore, it is desirable to have a mechanism that efficiently recoversreceived acknowledgement information to enhance network performance.

SUMMARY

The following summary illustrates a simplified version(s) of one or moreaspects of present invention. The purpose of this summary is to presentsome concepts in a simplified description as more detailed descriptionswill be presented later. In various exemplary embodiments, methods andapparatus are provided for efficiently detecting ACK/NACK bits receivedin LTE PUCCH format 3 uplink communications using Reed-Muller decodersand symbol regeneration.

In an exemplary embodiment, a method is provided for detected ACK/NACKbits received in a long-term evolution (LTE) physical uplink controlchannel (PUCCH) Format 3 uplink transmission. The method includesgenerating Top-M ACK candidates from a descrambled bit stream,regenerating Top-M candidate symbols from the Top-M ACK candidates,calculating channel estimates for the Top-M candidate symbols, combiningto the channel estimates generate a combined metric, and searching thecombined metric to determine detected ACK bits.

In an exemplary embodiment, an apparatus is provided for detectedACK/NACK bits received in a long-term evolution (LTE) physical uplinkcontrol channel (PUCCH) Format 3 uplink transmission. The apparatuscomprises a Top-M Reed Muller (RM) decoder that generates Top-M ACKcandidates from a descrambled bit stream, and a symbol regenerator thatregenerates Top-M candidate symbols from the Top-M ACK candidates. Theapparatus also comprises a channel estimator that calculates channelestimates for the Top-M candidate symbols, a combiner that combines thechannel estimates generate a combined metric, and a decision detectorthat searches the combined metric to determine detected ACK bits.

Additional features and benefits of the exemplary embodiment(s) of thepresent invention will become apparent from the detailed description,figures and claims set forth below.

BRIEF DESCRIPTION OF THE DRAWINGS

The exemplary aspect(s) of the present invention will be understood morefully from the detailed description given below and from theaccompanying drawings of various embodiments of the invention, which,however, should not be taken to limit the invention to the specificembodiments, but are for explanation and understanding only.

FIG. 1 is a block diagram illustrating a communication networkconfigured to transmit and receive data streams using variousembodiments of an ACK/NACK detector to detect ACK/NACK transmissions;

FIG. 2 shows diagrams illustrating channel coding processes;

FIG. 3 shows a block diagram of a receiver that comprises Reed Muller(32) or dual Reed Muller (24) decoders to detect ACK/NACK transmission;

FIG. 4 shows block diagrams of the Reed Muller decoding and bitdemapping for two scenarios handled by the receiver shown in FIG. 3;

FIG. 5 shows an embodiment of a receiver that comprises an exemplaryembodiment of an ACK/NACK detector;

FIG. 6 shows an exemplary embodiment of an ACK/NACK detector;

FIG. 7 shows an exemplary embodiment of the bit-extraction anddeinterleaver shown in FIG. 6 that utilizes a Top-M list-RDEC32 and aTop-M dual list-RDEC24;

FIG. 8 shows a detailed exemplary embodiment of the Top-M survivalcandidate symbol regenerator shown in FIG. 6;

FIG. 9 shows an exemplary embodiment of a method for detecting ACK/NACKbits using embodiments of an ACK/NACK detector as described herein; and

FIG. 10 illustrates an exemplary digital computing system with variousfeatures for network communication that include an ACK/NACK detector andassociated methods as described herein.

DETAILED DESCRIPTION

The purpose of the following detailed description is to provide anunderstanding of one or more embodiments of the present invention. Thoseof ordinary skills in the art will realize that the following detaileddescription is illustrative only and is not intended to be in any waylimiting. Other embodiments will readily suggest themselves to suchskilled persons having the benefit of this disclosure and/ordescription.

In the interest of clarity, not all of the routine features of theimplementations described herein are shown and described. It will, ofcourse, be understood that in the development of any such actualimplementation, numerous implementation-specific decisions may be madein order to achieve the developer's specific goals, such as compliancewith application- and business-related constraints, and that thesespecific goals will vary from one implementation to another and from onedeveloper to another. Moreover, it will be understood that such adevelopment effort might be complex and time-consuming but wouldnevertheless be a routine undertaking of engineering for those ofordinary skills in the art having the benefit of embodiment(s) of thisdisclosure.

Various embodiments of the present invention illustrated in the drawingsmay not be drawn to scale. Rather, the dimensions of the variousfeatures may be expanded or reduced for clarity. In addition, some ofthe drawings may be simplified for clarity. Thus, the drawings may notdepict all of the components of a given apparatus (e.g., device) ormethod. The same reference indicators will be used throughout thedrawings and the following detailed description to refer to the same orlike parts.

The term “system” or “device” is used generically herein to describe anynumber of components, elements, sub-systems, devices, packet switchelements, packet switches, access switches, routers, networks, modems,base stations, eNB (eNodeB), computer and/or communication devices ormechanisms, or combinations of components thereof. The term “computer”includes a processor, memory, and buses capable of executing instructionwherein the computer refers to one or a cluster of computers, personalcomputers, workstations, mainframes, or combinations of computersthereof.

In this description, IP communication network, IP network, orcommunication network means any type of network having an access networkthat is able to transmit data in a form of packets or cells, such as ATM(Asynchronous Transfer Mode) type, on a transport medium, for example,the TCP/IP or UDP/IP type. ATM cells are the result of decomposition (orsegmentation) of packets of data, IP type, and those packets (here IPpackets) comprise an IP header, a header specific to the transportmedium (for example UDP or TCP) and payload data. The IP network mayalso include a satellite network, a DVB-RCS (Digital VideoBroadcasting-Return Channel System) network, providing Internet accessvia satellite, or an SDMB (Satellite Digital Multimedia Broadcast)network, a terrestrial network, a cable (xDSL) network or a mobile orcellular network (GPRS/EDGE, or UMTS (where applicable of the MBMS(Multimedia Broadcast/Multicast Services) type, or the evolution of theUMTS known as LTE (Long-Term Evolution), or DVB-H (Digital VideoBroadcasting-Handhelds)), or a hybrid (satellite and terrestrial)network.

FIG. 1 is a block diagram illustrating a communication network 100configured to transmit and receive data streams using variousembodiments of an ACK/NACK detector (AND) 152 to detect ACK/NACKtransmissions. The network 100 includes packet data network gateway(“P-GW”) 120, two serving gateways (“S-GWs”) 121-122, two base stations(or cell sites) 102-104, server 124, and Internet 150. P-GW 120 includesvarious components 140 such as billing module 142, subscribing module144, tracking module 146, and the like to facilitate routing activitiesbetween sources and destinations. It should be noted that the underlyingconcept of the exemplary embodiment(s) of the present invention wouldnot change if one or more blocks (or devices) were added to or removedfrom diagram 100.

The network configuration illustrated by the communication network 100may also be referred to as a third generation (“3G”), 4G, LTE, 5G, orcombination of 3G and 4G cellular network configuration. MME 126, in oneaspect, is coupled to base stations (or cell site) and S-GWs capable offacilitating data transfer between 3G and LTE or between 2G and LTE. MME126 performs various controlling/managing functions, network securities,and resource allocations.

In an embodiment, the S-GW 121 or 122, in one example, coupled to P-GW120, MME 126, and base stations 102 or 104, is capable of routing datapackets from base station 102, or eNodeB, to P-GW 120 and/or MME 126. Afunction of S-GW 121 or 122 is to perform an anchoring function formobility between 3G and 4G equipment. S-GW 122 is also able to performvarious network management functions, such as terminating paths, pagingidle UEs, storing data, routing information, generating replica, and thelike.

In an embodiment, the P-GW 120, coupled to S-GWs 121-122 and Internet150, is able to provide network communication between user equipment(“UE”) and IP based networks such as Internet 150. P-GW 120 is used forconnectivity, packet filtering, inspection, data usage, billing, or PCRF(policy and charging rules function) enforcement, et cetera. P-GW 120also provides an anchoring function for mobility between 3G and 4G (orLTE) packet core network(s).

Sectors or blocks 102-104 are coupled to a base station or FEAB 128,which may also be known as cell site, node B, or eNodeB. Sectors 102-104include one or more radio towers 110 or 112. Radio tower 110 or 112 isfurther coupled to various UEs, such as a cellular phone 106, a handhelddevice 108, tablets and/or iPad® 107 via wireless communications orchannels 137-139. Devices 106-108 can be portable devices or mobiledevices, such as iPhone®, BlackBerry®, Android®, and so on. Base station102 facilitates network communication between mobile devices such as UEs106-107 with S-GW 121 via radio towers 110. It should be noted that basestation or cell site can include additional radio towers as well asother land switching circuitry.

Server 124 is coupled to P-GW 120 and base stations 102-104 via S-GW 121or 122. In one embodiment, server 124 which contains a soft decodingscheme is able to distribute and/or manage soft decoding and/or harddecoding based on predefined user selections. In one exemplary instance,upon detecting a downstream push data 130 addressing to mobile device106 which is located in a busy traffic area or noisy location, basestation 102 can elect to decode the downstream using the soft decodingscheme distributed by server 124. One advantage of using the softdecoding scheme is that it provides more accurate data decoding, wherebyoverall data integrity may be enhanced.

When receiving bit-streams via one or more wireless or cellularchannels, a decoder can optionally receive or decipher bit-streams withhard decision or soft decision. A hard decision is either 1 or 0 whichmeans any analog value greater than 0.5 is a logic value one (1) and anyanalog value less than 0.5 is a logic value zero (0). Alternatively, asoft decision or soft information can provide a range of value from 0,0.2, 0.4, 0.5, 0.6, 0.8, 0.9, and the like. For example, softinformation of 0.8 would be deciphered as a highly likelihood one (1)whereas soft information of 0.4 would be interpreted as a weak zero (0)and maybe one (1).

A base station, in one aspect, includes one or more FEAB s 128. Forexample, FEAB 128 can be a transceiver of a base station or eNodeB. Inone aspect, mobile devices such tables or iPad® 107 uses a first type ofRF signals to communicate with radio tower 110 at sector 102 andportable device 108 uses a second type of RF signals to communicate withradio tower 112 at sector 104. After receiving RF samples, FEAB 128 isable to process samples using an ACK/NACK detector (AND) 152 thatdetects received ACK/NACK bits in LTE PUCCH format 3 uplinktransmissions as described in greater detail below.

Table 1 illustrates PUCCH format 3 and specifies two coding scenariosdepending on the number of ACK bits, [N_(A/N) ^(PUCCH format 3)≤11]using a single Reed Muller (RM) coding and [11<N_(A/N)^(PUCCH format 3)≤22] using interleaved dual RM coding.

TABLE 1 Features of PUCCH format 3. Format Channel coding Modln (Bits)Format Reed Muller QPSK 3N_(A/N) ^(PUCCH format 3) ≤ 11 Format 3Interleaved dual Reed QPSK 11 < N_(A/N) ^(PUCCH format 3) ≤ 22 Muller

FIG. 2 shows diagrams illustrating channel coding processes. Asillustrated at 202, when N_(A/N) ^(PUCCH format 3)≤11, the ACKinformation bits are coded with a single RM32 code and circularlyrepeated to generate 48-bit encoded bits.

As illustrated at 204, when 11<N_(A/N) ^(PUCCH format 3)≤22, the ACKinformation bits are first separated and then encoded with dual RM24code bits. The results are then interleaved by an interleaver togenerate 48-bit interleaved encoded bits.

FIG. 3 shows a block diagram of a receiver 300 that comprises RM32 ordual RM24 decoders to detect ACK/NACK transmission. A front-end receiver302 receives uplink transmissions and performs front end fast Fouriertransform (FFT) processing to extract data and pilot information. Thedata information is input to a data symbol processor 304 and the pilotinformation is input to a pilot symbol processor 308.

A whitening coefficient calculator 306 generates whitening coefficientsfor both the pilot symbol processor 308 and the data symbol processor304. The pilot symbol processor 308 performs pilot AFC processing andwhitening to generate processed pilot information that is input to apilot channel estimator 312. The pilot channel estimator 312 generateschannel estimates that are input to a data channel compensator 310. Thedata symbol generator 304 performs DFT, dispreading, and channelwhitening to generate processed data symbols that also are input to thedata channel compensator 310.

The data channel compensator 310 outputs compensated data to a diversityMRC block, which outputs scrambled data (e.g., {tilde over (d)}(0), . .. , {tilde over (d)}(23)) to a demodulator/descrambler 316 thatgenerates demodulated/descrambled data ({tilde over (b)}₀,{tilde over(b)}₁,{tilde over (b)}₂, . . . , {tilde over (b)}₄₇), which is input toa demapper 318. The demapper 318 performs Reed Muller 32-bit decoding(RDEC32) for NACK<=11 and dual Reed Muller 24-bit decoding (RDEC24) for11<NACK<=22. In an embodiment, the demapper 318 comprises a dual RMdeinterleaver, dual RDEC24 and bit demapper to generate the detected ACKbits ({circumflex over (0)}_(i) ^(ACK)) and a reliability indicator.

FIG. 4 shows block diagrams of the Reed Muller decoding and bitdemapping for two scenarios handled by the receiver 300 shown in FIG. 3.The decode bit mapper 318 operates so that the ACK bits will beextracted and decoded depending on the number of ACK bits. As shown atthe block diagram 400, for N_(A/N) ^(PUCCH format 3)≤11, the 32 softbits are extracted from {tilde over (b)}₀, {tilde over (b)}₁, {tildeover (b)}₂, . . . , {tilde over (b)}₄₇ and passed to the RDEC32. TheRDEC32 will produce the decoded ACK bits [ô_(i) ^(ACK)].

As shown at the block diagram 402, for the case of 11<N_(A/N)^(PUCCH format 3)≤22, the soft-bits will be deinterleaved to generatethe input to dual RDEC24 decoders. Each half then will produce thecorresponding decoded bits. The decoded bits will then be demapped bybit demappers to create the final output bits [ô_(i) ^(ACK)].

FIG. 5 shows an embodiment of a receiver 500 that comprises an exemplaryembodiment of an ACK/NACK detector 502. For example, the AND 502 issuitable for use as the AND 152 shown in FIG. 1. In an exemplaryembodiment, the receiver 500 is configured similarly to the receiver 300shown in FIG. 3, except that the decode bit demapper 318 is replacedwith the AND 502. The AND 502 receives the descrambled bits 508 outputfrom the demodulator/descrambler 316. The AND 502 also receives pilotchannel coefficients 504 output from the pilot channel estimator 312.For example, in an exemplary embodiment, the pilot channel coefficients504 are generated from the following expression.

${{\hat{H}}_{Pilot}^{\overset{˜}{\rho},q}( {n_{NN},\ I_{p}} )} = \{ \begin{matrix}{{{\overset{˜}{R}}_{{whiten}_{-}P}^{\overset{˜}{\rho},q}( {n_{ss},l_{P}} )}/12} \\{{{\overset{˜}{R}}_{AFC}^{\overset{˜}{\rho},q}( {n_{ss},l_{P}} )}/12}\end{matrix} $

Additionally, the AND 502 receives data symbol information 506 outputfrom the data symbol processor 304. During operation, the AND 502processes the received signals to generate ACK bits 510 and reliabilityindicator 512.

In an exemplary embodiment, the AND 502 comprises a multi-stage list-RMdecoder or dual list-RM decoders that are followed by a symbol levelmaximum likelihood search of the survival candidates from an initialdetection of list-based RM32 or dual RM24 Reed Muller decoders. A moredetailed description of the AND 502 is provided below.

FIG. 6 shows an exemplary embodiment of an ACK/NACK detector 600. Forexample, the AND 600 is suitable for use as the AND 502 shown in FIG. 5.In an embodiment, the AND 600 comprises bit extraction/deinterleaver(BED) 602, Top-M symbol regenerator 604, Top-M maximum likelihood (ML)joint channel estimator and metric calculator (CEMC) 606 and decisiondetector 608. In an embodiment, M is a selectable integer value. In anembodiment, the CEMC 606 comprises the joint channel estimator 610,combiner 612, ML metric calculator 614 and maximal-ratio-combining (MRC)combiner 616.

In an embodiment, the BED 602 receives the descrambled bits 508 from thedemodulator/descrambler 316 and performs bit extraction/deinterleavingand Reed Muller decoding to generate Top-M candidate ACK bits 618

[Ô_(i ϵ[0, N_(A/N)^(PUCCHformat  3) − 1], M)^(ACK)]

that are input to the Top-M symbol regenerator 604.

In an embodiment, the Top-M symbol regenerator 604 receives the Top-Mcandidate ACK bits and generates Top-M regenerated symbols 620{combining breve ({circumflex over (d)})}(0), . . . , {combining breve({circumflex over (d)})}(23) that are input to the joint channelestimator 610 that is part of the CEMC 606.

In an embodiment, the joint channel estimator 610 receives the Top-Mregenerated symbols 620 and the data symbols information 506, andgenerates a joint channel estimate for the regenerated data symbols thatis input to the combiner 612. For example, in an exemplary embodiment,the joint channel estimate is generated from the following expression.

{tilde over (H)} _(Data) ^([0, M−1])(n _(SS) , i′)={tilde over (R)}_(Data) ^({tilde over (p)}, q)(n _(SS) , i′){combining breve ({circlearound (d)})}(n _(SS) *N _(SC) ^(RB) +i′)_(regen) ^([0, M−1])

i′ ∈ [0, 11], n_(SS) ∈ [0, 1]

In an embodiment, the combiner 612 receives pilot estimate information504 from the pilot channel estimator 312 and the joint channel estimatefrom the channel estimator 610 and generates a combined estimate that isinput to the metric calculator 614.

In an embodiment, the ML metric calculator 614 receives the combinedchannel estimates and generates a ML metric that is input to the metricMRC combiner 616. For example, in an exemplary embodiment, the ML metricis generated from the following expression that includes the combinedchannel estimate.

${MetricEng}_{\lbrack{0:{M - 1}}\rbrack}^{\overset{˜}{\rho},q} = {\sum\limits_{n_{SS}}\{ {{\sum\limits_{i^{\prime}}{{{\overset{\sim}{H}}_{{Data}{\lbrack{0:{M - 1}}\rbrack}}^{\overset{\sim}{p},q}( {n_{SS},i^{\prime}} )}}^{2}} + {\sum\limits_{l_{P}}{{{\overset{\sim}{H}}_{Pilot}^{\overset{\sim}{p},q}( {n_{SS},l_{P}} )}}^{2}}} \}}$     i′ ∈ [0, 11], n_(SS)ϵ[0, 1]

In an embodiment, the MRC combiner 616 receives the ML metric for theTop-M candidates and generates MRC combined metric 622 that is input tothe decision detector 608. For example, in an exemplary embodiment, theMRC combined estimate is generated from the following expression.

${MetricEng_{\lbrack{0:{M - 1}}\rbrack}^{MRC}} = {\sum\limits_{\overset{˜}{\rho}}{\sum\limits_{q}{MetricEng_{\;^{\lbrack{0:{M - 1}}\rbrack}}^{\overset{˜}{\rho,}q}}}}$

In an embodiment, the decision detector 608 receives the MRC combinedmetric 622 and performs a search, compare and decision process to detectthe final ACK bits [ô_(i) ^(ACK)] 510 and the reliability indicator 512.For example, the decision detector 608 determines ĵ_(MAX) from thefollowing expression.

ĵ _(MAX)=argmax[MetricEng_(j) ^(MRC)]

The decision detector 608 then determines the final ACK bits from thefollowing expression.

Ô_(i ϵ[0, N_(A/N)^(PUCCHformat  3) − 1])^(ACK, Final) = Ô_(i ϵ[0, N_(A/N)^(PUCCHformat  3) − 1])^(ACK), ĵ_(MAX)

FIG. 7 shows an exemplary embodiment of the bit-extraction anddeinterleaver 602 shown in FIG. 6 that utilizes a Top-M list-RDEC32 702and Top-M dual list-RDEC24 704.

When NACK<=11, the Top-M list RDEC32 702 utilizes a 32-bit extractor 706that receives the descrambled bits 508 and extracts 32-bits that areinput to a Top-M list RDEC32 decoder 708. The RDEC32 decoder 708generates the Top-M survival candidates 618 [{circumflex over(0)}_(i∈[0,N) _(A/N) _(PUCCHformat3) _(−1], M) ^(ACK)].

When 11<NACK<=22, the Top-M dual list-RDEC24 704 utilizes a dual RMdeinterleaver 710 to receive the descrambled bits 508 and generate twosets of deinterleaved bits. A first set of deinterleaved bits is inputto a first Top-M RDEC24 decoder 712, and a second set of deinterleavedbits is input to a second Top-M RDEC24 decoder 714. The Top-M decodedbits are input to corresponding Top-M bit demappers 716 and 718 thatreorder the bits. The output from the demappers 716, 718 form the Top-Msurvival candidates 618

[Ô_(i ϵ[0, N_(A/N)^(PUCCHformat  3) − 1], M)^(ACK)].

FIG. 8 shows a detailed exemplary embodiment of the Top-M survivalcandidate symbol regenerator 604 shown in FIG. 6. In an embodiment, theregenerator 604 comprises channel coder 802, scrambler 804 and QPSKmodulator 806.

In an embodiment, the channel coder 802 receives the Top-M survivalcandidates 618 and performs channel coding using a RM32 or dual RM24coders. For example, the channel coder 802 generate coded Top-M survivalcandidates that are input to the scrambler 804.

In an embodiment, the scrambler 804 scrambles the coded Top-M survivalcandidates and performs a scrambling process to generate scrambled Top-Mcandidates that are input to the QPSK modulator 806.

In an embodiment, the QPSK modulator 806 modulates the scrambled Top-Mcandidates to generate Top-M regenerated symbols 620. As illustrated inFIG. 6, these regenerated symbols are input to the joint channelestimator 610.

FIG. 9 shows an exemplary embodiment of a method 900 for detectingACK/NACK bits using embodiments of an ACK/NACK detector as describedherein. For example, the method 900 is suitable for use with the AND 152shown in FIG. 1 and the AND 502 shown in FIGS. 5-8.

At block 902, a receiver is operated to generate a descrambled bitstream from a received LTE PUCCH format 3 uplink transmission. Thereceived uplink transmission includes ACK/NACK values. For example, inan embodiment, the receiver 500 receives and processes the uplinktransmissions. The demodulator/descrambler 316 generates the descrambledbit stream 508.

At block 904, Top-M ACK candidates are generated from the descrambledbit stream. For example, the bit extractor/deinterleaver 602 receivesthe descrambled bit stream 508 and generates the Top-M ACK candidates618.

At block 906, Top-M candidate symbols are generated from the Top-M ACKcandidates. For example, the Top-M symbol generator 604 generates theTop-M candidate symbols from the Top-M ACK candidates.

At block 908, a combined metric associated with the Top-M candidatesymbols is generated. For example, the CEMC 606 receives the Top-Mcandidate symbols 620 and generates the combined metric 622.

At block 910, the combined metric is searched to determine detected ACKbits. For example, the ML survival metric searcher 608 searches thecombined metric 622 and generates the detected ACK bits 510.

Thus, the method 900 operates to detect ACK bits in a received LTE PUCCHformat 3 uplink transmission. It should be noted that the operations ofthe method 900 may be added to, subtracted from, deleted, changed,rearranged or otherwise modified within the scope of the embodiments.

FIG. 10 illustrates an exemplary digital computing system 1000 withvarious features for network communication that include an ACK/NACKdetector 1030 and associated methods as described herein. It will beapparent to those of ordinary skill in the art that other alternativecomputer system architectures may also be employed.

Computer system 1000 includes a processing unit 1001, an interface bus1012, and an input/output (“IO”) unit 1020. Processing unit 1001includes a processor 1002, main memory 1004, system bus 1010, staticmemory device 1006, bus control unit 1005, and mass storage memory 1007.Bus 1010 is used to transmit information between various components andprocessor 1002 for data processing. Processor 1002 may be any of a widevariety of general-purpose processors, embedded processors, ormicroprocessors such as ARM° embedded processors, Intel® Core™ 2 Duo,Core™ 2 Quad, Xeon®, Pentium™ microprocessor, AMD® family processors,MIPS® embedded processors, or Power PC™ microprocessor.

Main memory 1004, which may include multiple levels of cache memories,stores frequently used data and instructions. Main memory 1004 may beRAM (random access memory), MRAM (magnetic RAM), or flash memory. Staticmemory 1006 may be a ROM (read-only memory), which is coupled to bus1011, for storing static information and/or instructions. Bus controlunit 1005 is coupled to buses 1010-1012 and controls which component,such as main memory 1004 or processor 1002, can use the bus. Massstorage memory 1007 may be a magnetic disk, solid-state drive (“SSD”),optical disk, hard disk drive, floppy disk, CD-ROM, and/or flashmemories for storing large amounts of data.

I/O unit 1020, in one example, includes a display 1021, keyboard 1022,cursor control device 1023, decoder 1024, and communication device 1025.Display device 1021 may be a liquid crystal device, flat panel monitor,cathode ray tube (“CRT”), touch-screen display, or other suitabledisplay device. Display 1021 projects or displays graphical images orwindows. Keyboard 1022 can be a conventional alphanumeric input devicefor communicating information between computer system 1000 and computeroperator(s). Another type of user input device is cursor control device1023, such as a mouse, touch mouse, trackball, or other type of cursorfor communicating information between system 1000 and user(s).

Communication device 1025 is coupled to bus 1012 for accessinginformation from remote computers or servers through wide-area network.Communication device 1025 may include a modem, a router, or a networkinterface device, or other similar devices that facilitate communicationbetween computer 1000 and the network. In one aspect, communicationdevice 1025 is configured to perform wireless functions.

In one embodiment, AND 1030 is coupled to bus 1010 and is configured todetect ACK/NACK bits in received uplink transmissions. In variousexemplary embodiments, the AND 1030 comprises hardware, firmware, or acombination of hardware, and firmware. In an exemplary embodiment, theAND 1030 and communication device 1025 perform data reception andACK/NACK bit detection in accordance with one or more embodiments of thepresent invention.

While particular embodiments of the present invention have been shownand described, it will be obvious to those skilled in the art that,based upon the teachings herein, changes and modifications may be madewithout departing from this exemplary embodiment(s) of the presentinvention and its broader aspects. Therefore, the appended claims areintended to encompass within their scope all such changes andmodifications as are within the true spirit and scope of this exemplaryembodiment(s) of the present invention.

What is claimed is:
 1. A method for identifying network controlinformation during data transmission via a communication network, themethod comprising: receiving a bit stream from a physical uplink controlchannel (“PUCCH”) via a communication network; descrambling the bitstream to generate a descrambled bit stream containing controlinformation relating to acknowledgement (“ACK”); identifying andextracting a first set of bits from the descrambled bit stream when anumber of ACK bits is in a first range of bit numbers; and generatingACK candidates in response to the first set of bits of the descrambledbit stream via a first Reed Muller decoder capable of decoding the firstset of bits.
 2. The method of claim 1, wherein identifying andextracting a first set of bits includes extracting 32 bits from thedescrambled bit stream when a number of ACK bits is less than or equalto
 11. 3. The method of claim 2, wherein generating ACK candidatesincludes providing ACK candidates in response to the 32 bits of thedescrambled bit stream via a Reed Muller 32-bit decoder.
 4. The methodof claim 1, further comprising deinterleaving the descrambled bit streamto generate first and second sets of deinterleaved bits when a number ofACK bits is in a second range of bit numbers.
 5. The method of claim 4,further comprising performing a second Reed Muller decoder able todecoding the second range of bit numbers.
 6. The method of claim 4,wherein deinterleaving the descrambled bit stream further includesgenerating the first and the second sets of deinterleaved bits when thenumber of ACK bits is in a range of 12 to
 22. 7. The method of claim 5,wherein performing a second Reed Muller decoder includes generating eachof the first and second sets of deinterleaved bits via two Reed Muller24-bit decoders to generate a first and a second sets of decoded bits.8. The method of claim 5, further comprising demapping the first andsecond sets of decoded bits to generate ACK candidates.
 9. The method ofclaim 1, further comprising regenerating Top-M candidate symbols inaccordance with the ACK candidates and calculating channel estimatesbased on the Top-M candidate symbols.
 10. The method of claim 9, furthercomprising combining to the channel estimates generate a combined metricand searching the combined metric to determine detected ACK bits. 11.The method of claim 9, wherein regenerating Top-M candidate symbolsincludes performing one of a RM32 coding or dual RM24 coding on Top-Mcandidate bits; and scrambling the Top-M candidate bits to generatescrambled Top-M candidate bits.
 12. The method of claim 9, whereincalculating the channel estimates includes generating a joint channelestimate based on received data symbols and the Top-M candidate symbolsand combining the joint channel estimate with a pilot channel estimateto generate a combined Top-M channel estimate.
 13. The method of claim9, wherein calculating the channel estimates includes calculating an MLmetric from the combined Top-M channel estimate; and combining the MLmetric to generate to generate the combined metric.
 15. The method ofclaim 1, further comprising providing a set of ACK bits with areliability indicator in response to the ACK candidates.
 16. A methodfor identifying network control information during data transmission viaa communication network, the method comprising: receiving a bit streamfrom a physical uplink control channel (“PUCCH”) via a communicationnetwork; descrambling the bit stream to generate a descrambled bitstream containing control information relating to negativeacknowledgement (“NACK”); deinterleaving the descrambled bit stream togenerate first and second sets of deinterleaved bits when a number ofNACK bits is in a range of 12 to 22; performing a Reed Muller 24-bitdecode on each of the first and second sets of deinterleaved bits togenerate first and second sets of decoded bits; and demapping the firstand second sets of decoded bits to generate Top-M NACK candidates. 17.The method of claim 16, further comprising identifying and extracting 32bits from the descrambled bit stream when a number of Top-M NACK bits isless than
 12. 18. The method of claim 17, further comprising generatingTop-M NACK candidates in response to the 32 bits of the descrambled bitstream via a Reed Muller 32-bit decoder.
 19. The method of claim 16,further comprising regenerating Top-M candidate symbols in accordancewith the Top-M NACK candidates and calculating channel estimates basedon the Top-M candidate symbols.
 20. The method of claim 19, furthercomprising combining to the channel estimates generate a combined metricand searching the combined metric to determine detected NACK bits. 21.The method of claim 19, wherein regenerating Top-M candidate symbolsincludes performing one of a RM32 coding or dual RM24 coding on Top-Mcandidate bits; and scrambling the Top-M candidate bits to generatescrambled Top-M candidate bits.
 22. A method for identifying networkcontrol information during data transmission via a communicationnetwork, the method comprising: receiving a bit stream from a physicaluplink control channel (“PUCCH”) via a communication network;descrambling the bit stream to generate a descrambled bit streamcontaining control information relating to acknowledgement (“ACK”);deinterleaving the descrambled bit stream to generate first and secondsets of deinterleaved bits when a number of ACK bits is in a range of 12to 22; performing a Reed Muller 24-bit decode on each of the first andsecond sets of deinterleaved bits to generate first and second sets ofdecoded bits; and demapping the first and second sets of decoded bits togenerate Top-M ACK candidates.
 23. The method of claim 22, furthercomprising identifying and extracting 32 bits from the descrambled bitstream when a number of Top-M ACK bits is less than
 12. 24. The methodof claim 23, further comprising generating Top-M ACK candidates inresponse to the 32 bits of the descrambled bit stream via a Reed Muller32-bit decoder.
 25. An apparatus for identifying network controlinformation during data transmission via a communication network, theapparatus comprising: means for receiving a bit stream from a physicaluplink control channel (“PUCCH”) via a communication network; means fordescrambling the bit stream to generate a descrambled bit streamcontaining control information relating to acknowledgement (“ACK”);means for identifying and extracting a first set of bits from thedescrambled bit stream when a number of ACK bits is in a first range ofbit numbers; and means for generating ACK candidates in response to thefirst set of bits of the descrambled bit stream via a first Reed Mullerdecoder capable of decoding the first set of bits.
 26. The apparatus ofclaim 25, wherein means for identifying and extracting a first set ofbits includes means for extracting 32 bits from the descrambled bitstream when a number of ACK bits is less than or equal to
 11. 27. Theapparatus of claim 26, wherein means for generating ACK candidatesincludes means for providing ACK candidates in response to the 32 bitsof the descrambled bit stream via a Reed Muller 32-bit decoder.
 28. Theapparatus of claim 25, further comprising means for deinterleaving thedescrambled bit stream to generate first and second sets ofdeinterleaved bits when a number of ACK bits is in a second range of bitnumbers.
 29. The apparatus of claim 28, further comprising means forperforming a second Reed Muller decoder able to decoding the secondrange of bit numbers.
 30. The apparatus of claim 28, wherein means formeans for deinterleaving the descrambled bit stream further includesmeans for generating the first and the second sets of deinterleaved bitswhen the number of ACK bits is in a range of 12 to 22.